High voltage power supplies are known to be useful in the ionization of selected gases such as air or nitrogen. Passing ionized gas over objects susceptible to static discharge prevents the accumulation of charge on the objects, and avoids occurrence of an undesirable discharge event. Accordingly, static voltages can be readily eliminated on objects which are sensitive to static discharge, and in objects which may develop strong mechanical forces as a result of charge accumulation, and in circumstances where static discharge may lead to fire, explosion, damage to the object, or risk of severe injury.
Certain known high voltage power supplies may use large AC transformers. Alternatively, high voltage supplies may user small, high frequency transformers driven by semiconductor circuits operating in packages of reduced size. However, the disadvantage of high voltage supplies using small high frequency transformers is that they generate substantial interference signals which propagate back to the power source and produce detrimental radio interference.
The radio interference thus produced is conventionally reduced by line filters which reduce the radio interference signal to an acceptable level. The line filters include shielded packaging containing capacitor and inductor circuitry which may be physically larger and more expensive than the power supply circuit itself.
Accordingly it is desirable to provide a power supply useful in gas ionization circuits which suppresses interference signals by its fundamental operating mode without the aid of shielding and filtering circuits.